NOAA: Above Average Precipitation in U.S. for September; South Much Cooler than Average, West Much Drier
October 10, 2008
September 2008 was the 49th warmest and 38th wettest on record for the contiguous United States, according to an analysis by NOAA’s National Climatic Data Center in Asheville, N.C., based on records dating back to 1895.
The average September temperature of 65.8 degrees F was 0.4 degree F above the 20th century average, based on preliminary data. Precipitation across the contiguous United States in September averaged 2.68 inches, which is 0.20 inch above the 1901-2000 average.
U.S. Temperature Highlights
- California had its 10th warmest September, while Texas had its 10th coolest September on record.
- The southern United States experienced its 11th coolest September on record, with an average temperature of 71.7 degrees F, 2.6 degrees below the 20th century mean.
- The western United States had its second warmest July-September period on record. California had its fourth warmest and Nevada its fifth warmest July-September stretch on record.
- Based on NOAA's Residential Energy Demand Temperature Index, the contiguous U.S. temperature-related energy demand was 1.7 percent below average in September.
U.S. Precipitation Highlights
- The United States measured below-average precipitation in areas west of the Rockies, and from Florida to Kentucky. However, the remnants of hurricanes Gustav, Hanna and Ike brought above average precipitation from Louisiana to Michigan and throughout the Northeast.
- California had its driest September on record, with an average of just 0.01 inch of precipitation – 0.45 inches below the 20th century average. Kentucky, Florida, Georgia, Nevada and Tennessee had one of their driest Septembers on record.
- Arkansas, Connecticut, Illinois, Louisiana, Maine, Massachusetts, Michigan, Missouri, New Hampshire, and Rhode Island experienced one of their 10 wettest Septembers on record.
- The remnants of hurricanes Gustav and Ike drenched areas from Missouri through Illinois and into southern Michigan with up to three times the normal September rainfall. Chicago’s O’Hare International Airport set its all-time calendar day record rainfall of 6.64 inches on September 13, while Portage, Ind., picked up 11.46 inches of rain from September 12-14.
- Drought conditions across the United States showed little change during September. According to the U.S. Drought Monitor, only slight improvements were seen in the mid-Atlantic region, parts of Texas and the northern tier of states, while minor worsening occurred in parts of the southeast, Tennessee and Ohio valleys, and Wisconsin. At the end of September, 24 percent of the contiguous United States was in moderate-to-exceptional drought. Meanwhile, extreme-to-exceptional drought persisted in the western Carolinas, western North Dakota, southern Texas, northern California and Hawai’i.
- Gustav, Hanna and Ike made landfall in the United States in September. Gustav struck as a Category 2 storm near Cocodrie, La. on September 1. Hanna came ashore near Myrtle Beach, S.C. as a tropical storm on September 6 and moved northeast along the Atlantic coast. Hurricane Ike made landfall at Galveston, Texas on September 13 as a Category 2 storm.
- Wildfire activity was well below average across the United States in September. Between August 29 and September 29, approximately 155,040 acres were scorched, which is the second lowest September total this decade and is nearly a half million acres below the 1999-2008 average. In September, 3,534 new wildfires were reported, according to the National Interagency Fire Center. This is the fewest number of fires in September during the past decade, and 2,820 fewer fires than the 1999-2008 average for the month.
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